This invention relates to the extermination or killing of weeds or undesirable amd noxious vegetation involving the use of electrical energy.
Weed killing methods and apparatus wherein electrical current is conducted through undesirable plants for the destruction of the same, are well known as disclosed, for example, in U.S. Pat. Nos. 492,635, 593,235 and 728,312. It is also recognized in the prior art that the external tissue layers of vegetation have relatively high electrical resistance as compared to the internal tissues protectively enclosed by the external layers or epidermis. Toward that end, electrical weed killing apparatus have been utilized with cutter implements so that the current may be conducted to the plants by the cutter blades after the plants are cut. The use of electrical weed killing means in association with cutter blades is disclosed, for example, in U.S. Pat. Nos. 593,235 and 728,312 aforementioned.
Abrading the surface of plants in preparation for growth control treatment is also well known as disclosed in U.S. Pat. No. 2,988,849 to Laughlin. According to the disclosure in the Laughlin patent, the external surfaces of plant leaves are abraded in order to remove coatings in preparation for injection or feeding of growth chemicals into the plant.
The extermination of weeds and other undesirable vegetation by electrical energy has heretofore required the supply of large electrical voltages for plant destruction purposes. While lower power consumption of electrical energy may be required in connection with the use of cutter implements, the power consumed by the operation of the cutter device cancels any power savings effected. Further, cutting of vegetation in connection with any weed killing operation may be undesirable. Although abrading of leaf surfaces is known, as disclosed in the Laughlin patent aforementioned, the abrading of plant stems or stalks to the extent necessary for removal of a high electrically resistant external layer, in order to expose lower electrically resistant plant tissues, in combination with prolonged electrode contact has not been taught by the prior art in connection with electrical weed killing operations despite the tremendous amount of invention activity that has characterized agricultural technology for many years. It is, therefore, an important object of the present invention to provide a more effective electrical weed killing operation achieved more economically then heretofore possible from an energy consumption standpoint.